Adding C++ to Projects I Didn't Make

So I want to edit Hello Neighbor Alpha 2 and I extracted the files from the Pak in a game copy. (Unreal Engine version 4.9 and my version I’m trying to use to open it is 4.9.2) When I try to open the project, this message pops up:

The following modules are missing or built with another different engine version:

UE4Editor-HelloNeighborReborn.dll

Would you like to rebuild them now?

So when I click yes, all that pops up is this:

HelloNeighborReborn could not be compiled. Try rebuilding from source manually.

I have been trying so hard to open the project, but I can’t find any way how to open it in Unreal Engine. I did not create the project obviously, so I can’t open it in the editor. I also tried opening it in Visual Studio 2013, but it says it’s missing source code. It says:

This project does not have any source code. You need to add C++ source files from the Editor before you can generate project files.

But the thing is, I can’t open it up in the editor. I’m stuck and I can’t find anywhere that tells me how to fix this problem. I am a newbie at Unreal Engine, so I apologize if it’s not possible and made myself look stupid. But I really want to open the game up to modify the build. If it’s possible, please let me know! Thanks! :slight_smile:

If someone else can confirm - but you will be able to open the files in the mod kit but the source code has not been provided so you will not be able to open in unreal engine itself.

Correct, you cannot casually open project of someone else without the source code and Blueprint assets.

I have the same problem too. I see people change the doors from mods and idk how they do it. So Is this problem solvable?